Fix coupon form a bit

res/template/fragments/form.html

@@ -9,7 +9,6 @@
 				</div>
 			{{else}}
 				<div id="submit_result" class="highlight_red">
-					Something went wrong, please correct these errors before continuing:<br/>
 					<ul>
 						{{range $msg := .SubmitMessages}}
 							<li>{{$msg}}</li>

webcontroller/subscription_activate.go

@@ -226,6 +226,15 @@ func (wc *WebController) couponForm(td *TemplateData, r *http.Request) (f Form)
 		return f
 	}
 
+	if !td.Authenticated {
+		f.Submitted = true
+		f.SubmitMessages = []template.HTML{
+			`You need to log in to a pixeldrain account to use the coupon. ` +
+				`<a href="/login">Click here to log in</a>`,
+		}
+		return f
+	}
+
 	if f.ReadInput(r) {
 		if err := td.PixelAPI.PostCouponRedeem(r.FormValue("code")); err != nil {
 			formAPIError(err, &f)

webcontroller/web_controller.go

@@ -193,8 +193,8 @@ func New(
 		{GET, "knoxfs_activate", wc.serveForm(wc.knoxfsLinkForm, handlerOpts{Auth: true})},
 		{PST, "knoxfs_activate", wc.serveForm(wc.knoxfsLinkForm, handlerOpts{Auth: true})},
 
-		{GET, "coupon_redeem", wc.serveForm(wc.couponForm, handlerOpts{Auth: true})},
-		{PST, "coupon_redeem", wc.serveForm(wc.couponForm, handlerOpts{Auth: true})},
+		{GET, "coupon_redeem", wc.serveForm(wc.couponForm, handlerOpts{})},
+		{PST, "coupon_redeem", wc.serveForm(wc.couponForm, handlerOpts{})},
 
 		// Admin settings
 		{GET, "admin" /*                */, wc.serveTemplate("admin", handlerOpts{Auth: true})},